This Wednesday, Oct. 11, 2017 satellite image using a Very Near Infrared (VNIR) provided by DigitalGlobe shows damage from the wildfire near Santa Rosa, Calif. VNIR imagery causes healthy vegetation to appear red and the burn scar from the wildfire to be dark brown. Wildfires whipped by powerful winds swept through Northern California sending residents on a headlong flight to safety through smoke and flames as homes burned. (Digital Globe via AP)

This Wednesday, Oct. 11, 2017 satellite image using a Very Near Infrared (VNIR) provided by DigitalGlobe shows damage from the wildfire near Santa Rosa, Calif. VNIR imagery causes healthy vegetation to appear red and the burn scar from the wildfire to be dark brown. Wildfires whipped by powerful winds swept through Northern California sending residents on a headlong flight to safety through smoke and flames as homes burned. (Digital Globe via AP)

This Tuesday, Oct. 10, 2017, satellite image using shortwave infrared (SWIR) provided by DigitalGlobe shows damage from the wildfire near Santa Rosa, Calif. SWIR imagery allows for the ability to see though smoke to identify active fires, top. Wildfires whipped by powerful winds swept through Northern California sending residents on a headlong flight to safety through smoke and flames as homes burned. (Digital Globe via AP)

The view of the downtown San Jose, Calif., is filled with a smoky haze seen from the 18th floor of San Jose City Hall Wednesday, Oct. 11, 2017. Officials say they have thousands of firefighters battling almost two dozen blazes burning in Northern California and that more are coming from nearby states. (Josie Lep/San Jose Mercury News via AP)

Tammy Christiansen searches the remains of her Coffey Park neighborhood home Wednesday, Oct. 11, 2017, in Santa Rosa, Calif. During her search she found her wedding ring and her son's wrestling trophy. Officials say they have thousands of firefighters battling 22 blazes burning in Northern California and that more are coming from nearby states. (AP Photo/Eric Risberg)

Neal O'Mara loads his pickup as he prepares to evacuate the town of Sonoma, Calif., Wednesday, Oct.11, 2017. With fires getting near, the town was placed under a voluntary evacuation order.(AP Photo/Rich Pedroncelli)

Burned out homes are seen Wednesday, Oct. 11, 2017, in Santa Rosa, Calif. Wildfires whipped by powerful winds swept through Northern California sending residents on a headlong flight to safety through smoke and flames as homes burned. (AP Photo/Jeff Chiu)

A rooster walks by one of several burned out vehicles after a wildfire destroyed a home and farm on Wednesday, Oct. 11, 2017, in Calistoga, Calif. Three days after the fires began, firefighters were still unable to gain control of the blazes that had turned entire Northern California neighborhoods to ash and destroyed thousands of homes and businesses. (Paul Kitagaki Jr./The Sacramento Bee via AP)

Chris Shiery pets his dog, Ruby, while waiting to evacuate the town of Sonoma, Calif., Wednesday, Oct. 11, 2017. With fires getting near, the town was placed under a voluntary evacuation order. (AP Photo/Rich Pedroncelli)

Marshall Hayman, 26, and his family stay after a mandatory evacuation order issued on Wednesday, Oct. 11, 2017, in Calistoga, Calif. He lost his home in Calistoga on the first day of the fire. Three days after the fires began, firefighters were still unable to gain control of the blazes that had turned entire Northern California neighborhoods to ash and destroyed thousands of homes and businesses. (Paul Kitagaki Jr./The Sacramento Bee via AP)

CORRECTS TO STAY INSTEAD OF ARE AT HOME Mason Heyman, 18, and his family stay after a mandatory evacuation order issued on Wednesday, Oct. 11, 2017, in Calistoga, Calif. Three days after the fires began, firefighters were still unable to gain control of the blazes that had turned entire Northern California neighborhoods to ash and destroyed thousands of homes and businesses. (Paul Kitagaki Jr./The Sacramento Bee via AP)

Burned by the Tubbs fire, only a pool remains among the ashes of an Old Redwood Highway complex near Mark West Springs Road, Wednesday, Oct. 11, 2017, in Santa Rosa, California. (Karl Mondon /San Jose Mercury News via AP)

Homes burned by a wildfire are seen Wednesday, Oct. 11, 2017, in Santa Rosa, Calif. Wildfires whipped by powerful winds swept through Northern California sending residents on a headlong flight to safety through smoke and flames as homes burned. (AP Photo/Jeff Chiu)

Charred ground and only a few pieces are the remains of the historic Fountaingrove Round Barn Wednesday, Oct. 11, 2017, in Santa Rosa, Calif. The barn was built in 1899 and was a hillside landmark. Three days after the fires began, firefighters were still unable to gain control of the blazes that had turned entire Northern California neighborhoods to ash and destroyed thousands of homes and businesses. (AP Photo/Eric Risberg)

Two women, sort through the rubble of the property on 106 West Gate Drive in Napa, Calif., on Wednesday, Oct. 11, 2017. The property is where an elderly couple, died during the fire last Sunday, Oct. 8, 2017. (Ray Chavez /San Jose Mercury News via AP)

Colby Clark of San Francisco, left, comforts her mother, Bonnie Trexler, after being escorted by law enforcement to her home in Silverado Highland to retrieve medicine and some personal items on Wednesday, Oct., 11, 2017 in Napa, Calif. Trexler was one of the lucky few who found that her home was spared from the devastating fire which burned homes around her Monday. (Randy Pench /The Sacramento Bee via AP)

This Tuesday, Oct. 10, 2017, satellite image using shortwave infrared (SWIR) provided by DigitalGlobe shows damage from the wildfire in Santa Rosa, Calif. SWIR imagery allows for the ability to see though smoke to identify active fires, top left. Wildfires whipped by powerful winds swept through Northern California sending residents on a headlong flight to safety through smoke and flames as homes burned. (Digital Globe via AP)

A couple makes their way into a Red Cross disaster relief center Wednesday, Oct. 11, 2017, in Santa Rosa, Calif. Three days after the fires began, firefighters were still unable to gain control of the blazes that had turned entire Northern California neighborhoods to ash and destroyed thousands of homes and businesses. (AP Photo/Eric Risberg)

Jim Merriman, right, and his wife Lu, have a meal while spending the evening at a Red Cross disaster relief center Wednesday, Oct. 11, 2017, in Santa Rosa, Calif. The couple had to evacuate from their home in the Mendocino Woods neighborhood of Santa Rosa. Three days after the fires began, firefighters were still unable to gain control of the blazes that had turned entire Northern California neighborhoods to ash and destroyed thousands of homes and businesses. (AP Photo/Eric Risberg)

Oakland Police officer Anh Nguyen spray paints the street to mark that a house in Calistoga, Calif., is vacant on Wednesday, Oct. 11, 2017. The entire historic town of Calistoga, population 5,000, was evacuated. Three days after the fires began, firefighters were still unable to gain control of the blazes that had turned entire Northern California neighborhoods to ash and destroyed thousands of homes and businesses. (Paul Kitagaki Jr./The Sacramento Bee via AP)

Flames burn along a ridge above Sonoma, Calif., Wednesday, Oct. 11, 2017. An advisory evacuation was issued for residents of the area as the fire moved toward the historic town. Officials say they have thousands of firefighters battling almost two dozen blazes burning in Northern California and that more are coming from nearby states. (AP Photo/Rich Pedroncelli)

Tammy Christiansen looks over her wedding ring that she found after searching the remains of her burned Coffey Park neighborhood home Wednesday, Oct. 11, 2017, in Santa Rosa, Calif. (AP Photo/Eric Risberg)

SONOMA, Calif. (AP) — Fueled by the return of strong winds, the wildfires tearing through California wine country exploded in size and number Wednesday as authorities ordered new evacuations and the death toll climbed to 23 — a figure expected to rise.

Three days after the fires began, firefighters were still unable to gain control of the blazes that had turned entire Northern California neighborhoods to ash and destroyed at least 3,500 homes and businesses.

"We are literally looking at explosive vegetation," said Ken Pimlott, chief of the California Department of Forestry and Fire Protection. "It is very dynamic. These fires are changing by the minute in many areas."

The entire historic town of Calistoga, population 5,000, was evacuated. In neighboring Sonoma County, authorities issued an evacuation advisory for part of the town of Sonoma and the community of Boyes Hot Springs. By that time, the streets were lined with cars packed with people fleeing.

"That's very bad," resident Nick Hinman said when a deputy sheriff warned him that the driving winds could shift the wildfires toward the town of Sonoma proper, where 11,000 people live. "It'll go up like a candle."

The wildfires are on their way to becoming the deadliest and most destructive in state history. And officials warned the worst was far from over.

"Make no mistake, this is a serious, critical, catastrophic event," Pimlott said.

The fires have burned through a staggering 265 square miles (686 square kilometers) of urban and rural areas. High winds and low humidity made conditions ideal for fire to ignite virtually anywhere on ground or brush.

Cal Fire spokesman Daniel Berlant said 22 wildfires were burning Wednesday, up from 17 the day before. As the fires grow, officials voiced concern that separate fires would merge into even larger infernos.

"We have had big fires in the past. This is one of the biggest, most serious, and it's not over," Gov. Jerry Brown said at a news conference Wednesday, alongside the state's top emergency officials.

They said 8,000 firefighters and other personnel were battling the blazes and more resources were pouring in from Arizona, Nevada, Washington and Oregon.

Flames have raced across the wine-growing region and the scenic coastal area of Mendocino farther north, leaving little more than smoldering ashes and eye-stinging smoke in their wake. Whole neighborhoods were leveled, leaving only brick chimneys and charred appliances to mark sites that were once family homes.

In Boyes Hot Springs, residents for days had watched the ridges over the west side of town to gauge how close the billowing smoke and orange flames of the wildfires had come. On Wednesday, the ridges themselves were obscured by the growing clouds of smoke.

Increasingly large pieces of gray ash drifted down on the community. Sirens wailed. Residents who had held out hope of staying at home, packed up to leave.

With fires advancing from several sides in Sonoma Valley, law enforcement officers on loan from other areas of Northern California barred residents of evacuated communities from returning to see how the homes and businesses had fared. Manned roadblocks blocked routes between Sonoma and devastated areas of Santa Rosa.

Alejandro Rodriguez had been evacuated from one tiny Sonoma Valley town, only to have deputies come to the neighborhood he had relocated to and tell residents there to pack up to go.

"I want to see my house, see if any things left," Rodriguez said, gesturing at officers at one roadblock. "They won't tell us nothing."

Sonoma County Sheriff Robert Giordano said hundreds of people were still reported missing. But officials believe many of those people will be found. Chaotic evacuations and poor communications over the past few days have made locating friends and family difficult.

The sheriff also expects the death toll to climb.

"The devastation is enormous," he said. "We can't even get into most areas."

Authorities say most of Sonoma County's 13 victims lived where steep, narrow roads wind through the hillsides with few ways out.

Helicopters and air tankers were assisting thousands of firefighters trying to beat back the flames. Until now, the efforts have focused on "life safety" rather than extinguishing the blazes, partly because the flames were shifting with winds and targeting new communities without warning.

In Southern California, cooler weather and moist ocean air helped firefighters gain ground against a wildfire that has scorched nearly 14 square miles (36 sq. kilometers).

Orange County fire officials said the blaze was 60 percent contained and full containment was expected by Sunday, although another round of gusty winds and low humidity levels could arrive late Thursday.

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Gecker reported from San Francisco. Associated Press writers Olga R. Rodriguez, Juliet Williams and Andrew Dalton in San Francisco contributed to this report.